0685 Safety Evaluation Of An Algorithm Determining Needs For Treatment In Obese Sleep Apnea Patient Awaiting Bariatric Surgery: Results Of A Prospective 1103 Patients Cohort Study

Abstract

Introduction: Screening for obstructive sleep apnea (OSA) is recommended before bariatric surgery. We developed an algorithm based on results of nocturnal oximetry and capillary gas. According to this algorithm, CPAP/BiPAP is prescribed only in severe OSA (ODI ≥ 25/h) and/or with features of hypoventilation. The objective of this prospective cohort study was to determine the safety of our algorithm comparing peri and post-operative outcomes in patients not receiving pre-operative treatment (without/ mild OSA (ODI < 10 /h: controls or ODI 10-24 /h: OSA untreated) and in those receiving CPAP/BiPAP (severe OSA: OSA treated or hypoventilation). Methods: We collected data from 1103 subjects undergoing bariatric surgery (447 controls; 358 OSA untreated, 289 OSA treated and 9 hypoventilation). For treated patients, a good CPAP/ BiPAP compliance was mandatory for surgery with treatment installed immediately after extubation and continued after. Peri and post-operative outcomes were compared according to apnea status with adjustment for the type of surgery when applicable. Results: Patients with severe OSA/hypoventilation were significantly older and heavier than other patients. Hypertension and diabetes were less prevalent in controls than in the other groups. No difference was found between the 3 groups regarding occurrence of 10 days reoperation and 30 days rehospitalisation. No difference was found regarding occurrence of cardiopulmonary complications except that admission to ICU was more frequent in patients with hypoventilation and occurrence of cardiac arrhythmia was higher in the OSA/hypoventilation treated patients than in the other groups (2.4%, 11.1 %, 0.4% and 0.6%, p = 0.01). OSA/hypoventilation patients had a longer length of stay in the recovery room (1.7 ± 0.5, 1.9 ± 0.6, 1.5 ± 0.5 and 1.5 ± 0.5 hours p<0.0001) and longer length of hospital stay (2.8 ± 1.8, 3.2 ± 1.1, 2.6 ±2.1 and 2.6 ±1.8 days, p<0.0001) than controls and OSA untreated patients. Conclusion: Our algorithm safely selects patients who don't need treatment before surgery, with no increase in risk of complications following bariatric surgery not treating OSA patients with mild/ moderate sleep apnea without hypoventilation. Patients with severe OSA/hypoventilation, even when correctly treated remain at higher risk of complications.